login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A245808 Monoprimatic permutable numbers: Numbers whose decimal digits can be arranged to form exactly one prime number. No leading zeros. 5

%I #26 Nov 03 2019 12:05:47

%S 2,3,5,7,11,14,16,19,23,29,32,34,35,38,41,43,47,53,59,61,67,74,76,83,

%T 89,91,92,95,98,101,103,104,106,109,110,112,115,121,130,134,140,143,

%U 145,151,154,160,166,188,190,211,223,227,229,232,233,235,236,253,257,263,269,272,275,278,287,289,292

%N Monoprimatic permutable numbers: Numbers whose decimal digits can be arranged to form exactly one prime number. No leading zeros.

%C The sequence takes a surprisingly large number of computations to generate since the number of permutations rises quickly with the number of digits. Generating the sequence is an excellent programming exercise since there are several approaches to calculate the same sequence. Regardless of approach, there are many ways to optimize the algorithms, so the sequence would be a good choice of assignment for a contest between programmers. The assignment also has some pitfalls, mainly due to the problem of how to handle leading zeros.

%C The sequence was originally explored for the development of two puzzles found in the science fiction novel "The Right Left" by Andreas Boe.

%D Andreas Boe, The Right Left, Amazon books, 2014.

%H Andreas Boe, <a href="/A245808/b245808.txt">Table of n, a(n) for n = 1..9596</a>

%e 190 -> 019 (forbidden), 091 (forbidden), 109 (prime), 190 (even), 901 (composite), 910 (even) -> Conclusion: One prime number.

%Y Cf. A246044 (Monoprimatic permutable primes), A246043 (Biprimatic permutable numbers), A246045 (Biprimatic permutable primes).

%K nonn,base

%O 1,1

%A _Andreas Boe_, Aug 22 2014

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 05:49 EDT 2024. Contains 371964 sequences. (Running on oeis4.)